Randall, 1840
Carapace subquadrate, convex, covered with transverse ridges and striae except for the cardiac and intestinal regions which are comparatively smooth. Front about half the breadth of the carapace, covered with granules, frontal margin nearly straight, slightly concave medially and concave near the inner orbital angle. Postfrontal crest with 4 blunt lobes, the median pair separated by a broader groove. Dorsal orbital border slightly sloping, ventral orbital border serrated. Antero-lateral margin slightly arched. Outerorbital tooth sharp, followed posteriorly by an acute triangular tooth, with a U-shaped notch between the teeth.
Chelipeds symmetrical, covered with fine striae. Merus with 3 distal teeth on its inner border. Carpus with a sharp tooth at the inner-distal angle. Palm smooth, with granules and striae on its dorsal surface. The immovable finger with granules on the dorsal surface; inner borders of the two fingers with irregular teeth, tips shaped like narrow spoons. The second ambulatory leg the longest; first, third, and fourth legs gradually decreasing in length. Merus with a subdistal spine on its anterior border, postero-distal angle with 2-3 small teeth; carpus with hairy ridges on the dorsal surface; propodus with rows of tomentum and spinules; dactylus with 2 rows of sharp spinules on both the anterior and the posterior borders.
First pleopod of the male strongly stout, trigonal distal half with blunt distal process. Abdomen triangular. Abdomen of the female rounded. Carapace length of the male 29 mm, breadth 33.5 mm; of the female, length 23.1 mm, breadth 27.3 mm. (Dai & Yang, 1991)
Type locality: Sandwich Island, Hawaiian Islands. According to Rathbun, 1906, 1918, this locality is probably erroneous.
Range: Japan - Tokyo Bay and Sagami Bay (Ortmann, 1894a), Shimoda (Stimpson, 1907, Sakai, 1935), Tateyama Bay, Shimoda and Kii Peninsula (Sakai, 1939), Hachijo-jima (Sakai, 1954), Sagami Bay (Sakai, 1965b), from Boso Peninsula, Tokyo Bay, Sagami Bay southwards to Kyushu (Sakai, 1976a), Yamagata Prefecture (Suzuki S., 1979), Nanki Shirahama (Miyake, 1983), Hakodate (Komai et al., 1992), Hachijo-jima, Izu-Oshima, Hayama, Izu Peninsula, Enoshima, Manazuru, simoda, Kii Nagashima, Ashizuri-misaki, Okinoerabu-jima and Yoron-jima (Muraoka, 1998); Korea - (Sakai, 1939, 1976), Inch'on, Zenra-nando, Keisho-nando, Keisho-hokudo and Ulchin (Kamita, 1941), Samcheog, Jugbyeon, Pohang, Dogdo Island, Ulreung Island, Hae-undae, Mijo Ri, Sangchuja Island, Sasu Island, Hoeng-gan Island, Jeju, Iho Ri, Moseulpo, Namweon, Seongsanpo, and Daeheugsan (Kim, 1973), Cheju-do (Kim & Chang, 1985); China - Ningbo and Xiamen (Shen, 1940b), Guangdong, Fujian and Zhejiang (Dai & Yang, 1991); Taiwan; North America - California and San Francisco (Ortmann, 1894a), from Oregon to Gulf of California; Lower California - Guadalupe Island (Rathbun, 1924d), Cedros Island (Schmitt, 1939); Galapagos Islands; Chile.